Yarn-tying device



Nov. 12, 1963 e; GEBALD ETAL 3,110,511

YARN-TYING DEVICE Filed May 1'7. 1961 v s Sheets-Sheet 1 Nov. 12, 1963 GJGEBALD ETALr 3,110,511

YARN-TYING DEVICE Filed May 1'7, 1961 3-Sheets-Sheet 2 Nov. 12, 1963 G. GEBALD ETAL 3,110,511

' YARN-TYING DEVICE Filed May 17. 1961 s Sheets-Sheet a FIG. I4 J0 United States Patent Ofilice 3 ,1 10,51 1 Patented Nov. 12, 1963 3,110,511 YARN-TYING DEVICE Gregor Gebald, Monchen-Gladbach-I-lolt, and Wilhelm Hermes, Rheydt, Germany, assignors to Walter Reiners, MonchenGladbach, Germany Filed May 17, 1961, Ser. No. 159,197 Claims priority, application Germany May 18, 196i) 4 lairns. (Cl. 239-12) Our invention relates to a yarn-tying device of the type described in US. Patent 2,981,559, for use in textile manufacture.

Such a device is provided with two tie beaks which operate to form a fishermans knot. In a knot of this type, each of the two yarn ends to be tied together is first given a simple individual knot through whose loop the other yarn end can glide. Since each yarn end has its own knot, the two knots can move toward each other during tightening of the loops until they touch each oth r and then prevent each other from gliding out of the loop of the adjacent yarn end. The two tie beaks serve to tension the yarn ends after the individual knots are formed. Thereafter the tie beaks loosen and release the respective yarn ends. Such release takes place after the individual knots are formed but before they are tightened together. The knotter is provided with a tensioni-ng member which moves on a straight line between the two tie beaks and which serve to push the individual knots together.

It has been found that the pushing together of the individual knots by the tensioning member may sometimes be defective because, under unfavorable circumstances, the tensioning member may prevent the individual knots from being fully pushed against each other due to the fact that the tensioning member itself may become located between these individual knots.

It is an object of our invention to reliably eliminate such shortcomings.

To this end, and in accordance with our invention, we provide the tensioning member with a groove or saddleshaped recess at the surface where the member enters into engagement with the yarn in the vicinity of the individual knots and at the location where these individual knots are tightened together when the tie is being completed.

The invention will be further described with reference to the embodiment of a yarn knotter according to the invention illustrated by way of example on the accompanying drawings in which:

FIGS. 1 through 8 illustrate schematically respectively different stages of the knotting operation according to the invention.

FIG. 9 shows in section a part of the tensioning member, taken along line IXIX of FIG. 14.

FIGS. 10 and 11 are partly sectional top views of the knotting device with the knot-forming components shown in respectively different positions.

FIGS. 12 and 13 show details of the knotter for illustrating the yarn path through the knotter.

FIG. 14 is a cross-sectional view of the knotter; and

FIG. 15 is a graph relating to the knottin-g performance.

FIG. 16 shows in section a ten-sioning member according to Patent 2,981,364, for comparison with FIG. 9.

Rotatably mounted in a cylindrical portion of the knotter housing 1 is a cup-shaped disc 3 (FIGS. l4, 10, 11), which has a hollow shaft 21 (FIG. 14) driven through a pair of angularly related spur gears 22, 23, of which the gear 23 is essentially a segment biased olookwise about its shaft 23a by means of a spring 19. The segment gear 23% is joined with a follower arm .25 resting against the periphery of a driving cam 24 mounted on a shaft 29 driven from a motor (not shown) to perform a single, full-turn rotation whenever the knotter is to enter into operation. Such single revolution may be accomplished by having connected between the motor and shaft 29 a single-revolution clutch, such as that illustrated at page 161 of Mechanism, by Joseph S. Beggs, McGraW- Hill, 1955.

The upper rim of the cup disc 3 is provided on part of its periphery with a toothed gear portion 4 (FIGS. 14, 10, 11) which is in meshing engagement with driving pinions 5 and 5a joined to respective tie beaks 25 and 27 for rotating and operating them. The beak members 26,

7 are provided with cheek members 50 and jaw members 51 pivoted at 52 (FIGS. 4, 9). The cup disc 3 is further provided with slots 6, 7 (FIG. 11) which extend from the cup rim to the slot bottom, the respective slot bottoms having different depths and serving for receiving the yarn ends to be tied together.

Mounted outside of the cup disc 3 and concentrically thereto are stationary sheet-metal members 8 which are likewise provided with yarn-receiving slots 9 and 1%} whoseislot bottoms are likewise spaced from the cup rim respectively different amounts (FIGS. 10 to 13). Mounted on the periphery of the circular housing portion 1 are two yarn clamps, each of which comprises a fixed pin 11 and a movable clamping member 12. Each clamping memher 12 forms one arm of a lever 14 rotatable about a fixed pivot pin .13. The other end of each lever 14 is engagea'ble withone of two slots 15 in the cylindrical wall of the cup disc 3. The levers 14 (FIG. 10) are biased at their pivots 13 to urge their ends 14 toward and into slots 15 and also urge clamps 12 away from pins 11. However When slots 15 rotate out of the range of ends 14, the opposite ends 12 become pressed against their respective pins 11 to clamp the yarn.

Located between the two tie beaks 26 and 27 is a forked tensioning member 17 having fork branches 17a and 17b (FIGS. 6 to 11 and 14). The tensioning member 17 is axially displaoeable and can be shifted into a position where the ends of fork branches 17a and 17b protrude toward the left (FIG. 14) beyond the location of the tie beaks. As will be explained, it is essential to the invention that the tensioning member have a cavity or saddle as shown at 17 c in FIG. 9.

The tensioning member 17 is driven by means of a lever 28 (FIG. 14) pivoted at 23a and controlled by another cam 30 fixedly mounted on the cam shaft 29. The tensioning member 17 is biased toward the right by means of a helical spring 31 positioned around the shaft and axially biased between pin 31a, fixed to the shaft of member '17, and abutment 31b in hollow shaft 21, thus urging member 17 to normally occupy the position shown in FIG. 14. The lever 28 engages the cam 31) through a cam follower provided with an adjustable set screw 41 which can be arrested in the proper position within a sleeve 43 by means of lock nut 42. The sleeve 4-3 is displaoea'ble in the lower end of lever 28 and transmits its cam-follower motion through a spring 44 onto the lever 28 whose bore 45 the sleeve 43 can freely glide during compression of the spring 44.

The yarn knotting operation takes place as follows.

The end portions a and b of the two yarn lengths to be tied together are first so positioned in readiness that the ends a and d point in different diretcions (FIG. 1). This may be accomplished by seizing and positioning devices operating, for example, by suction and which are well known in the art of textile winding machines. The yarn pieces a and b pass into the bight of the adjacent beaks 26 and 27 respectively. Now the cam shaft 29 (FIG. 14) is driven to perform one full revolution. The cam 24 fixed to shaft 29, acting through follower x25 and 3 gears 23, 22, drives the cup disc 3 in mesh with the pinions 5 and 5a, so that the tie beaks 26 and 27 perform mutually opposed rotations, thus reaching the respective positions illustrated in FIG. 2. During continued rotation the beaks 26, 27 pass into the position of FIG. 3 and form a loop in each yarn portion a, b. During further rotation of the tie beaks, the terminal ends 0 and d of respective yarn pieces a and b pass over and below respectively of the positionally fixed yarn pieces a and b (FTGS. 3 and 11), this being due to the different depths of the slots 6, 7 on the one hand and the slots 1, 10 (FIGS. 12, 13) on the other hand. I

Due to the fact that the tie beaks 26, 27 have in the meantime changed their rotational position, the knot loops are now ready to be stripped off, and the yarn ends 0 and d are seized and held fast between respective cheek and jaw members 50, 51 of the respective tie beaks 26, 27. During the subsequent stripping off of the loops, the knot is completed. The stripping is effected by a motion of the tensioning member 17 which now moves axially and linearly between the two tie beaks to a protruding position in a direction to the left of beaks 26, 27, as viewed in H6. 14. During this advancing motion the member 17 acts upon the yarn pieces a and b which is held between the slot 6 or 7, the yarn clamps 11, 12 and the tie beaks. Due to this action of member 17 the initially loose but completely looped individual knots are tightened and closed. The tie beaks now open and sever the ends 0, d in conventional manner, as described, for example in German Patent 920,119. Thereafter the tension member 17 acts upon the yarn portions (FIGS. 6 and 7) located between the tightened individual knots. Now the yarn pieces a and b can glide until their individual knots approach and touch each other (FIG. 8), thus forming the completed, knotted tie shown in FIG. 5.

The coaction of the individual operations described above is diagrammatically represented in the gnaph of FIG. where the abscissa denotes units of time t, the ordinate in the upper diagram portion denotes units of travel distance d, and the ordinate in the lower portion of the diagram denotes tensioning force F. The curve B indicates the travel motion of the tie beaks, the curve S the motion of the tension member 17, and the curve P the tension exerted by the member 17 upon the yarn.

The yarn pieces are placed in proper position during the time interval from i=0 to t=-1. In the time interval from 1-5 there occurs the formation of the loops by means of the tie beaks as described above. Thereafter the tension member 17 moves beyond the tie beaks to such an extent that the yarn pieces are stripped off the tie beaks and are thereafter slightly pulled, although at this stage the yarn ends to 'be tied together are not yet placed under tightening tension. This stage is apparent from FIG. 6. Between the time points 6 and 7, the tie beaks are moved back for a short interval of time and are simultaneously opened (FIG. 7). In the meantime the tension member 17, at the moment i=6, has reacted its first step of motion when cam hump 3la (FIG. 14) reaches the cam follower 41 (at 1311a in FIG. 15) and thus has tightened and closed the individual knots. Thereafter, after hump 311a passes the cam follower, the tension member 17 recedes a slight :amount to the right (as viewed in FIG. 14) under the action of spring 31. The tension curve P in FIG. 15 indicates accordingly that the tension first increases and then declines between the time points 6 and 7, the decline in tension being terminated before time point 7 is reached. After the opening of the beaks, namely between time points 7 and 8, another forward motion is imparted to the tensioning member -17 by hump 31th of cam reaching cam follower 41, and this motion, shown at 1311b of curve S (FIG. 15), now imposes a tensioning stress upon the tie connection. As a result the two individual knots approach each other, gliding along the yarn piece embraced by the individual loop of each knot (*FIG. 8). At Time 1. 1 9 motion of the tension member '17 is terminated and the tensioning force P reaches its maximum value, which then during the subsequent receding travel of the tension member again declines down to zero. The knotted tie is now completed and is also tested by means of the tension member 17. The yarn is released from the knotter and weaving, coil winding or other fabricating operation can be continued.

As mentioned above, the above-described knotting operation may result in defective knots if the tensioning member happens to penetrate between the two individual knots as they are being pulled together. This may correspond to the condition exemplified in FIG. 16. The tensioning member, here denoted by 117, is shown to have penetrated between the individual knots 101 and 1112 and to have been placed against the yarn ends a, b and yarn portions 0, d. Consequently, during the tightening operation the knots 101 and 102 cannot move fully against each other, so that the tie may subsequently become loose.

To prevent such trouble, and according to the present invention, we provide the tensioning member 17 (FIGS. 6 to 9) with a cavity 17c or a saddle at the location where the individual knots 1G1 and 1112 are situated when they are tightened together. The active end surface of the tensioning member thus has a cavity formed by a ring-shaped bulge 17'. However, in lieu of such a circular cavity, the recess 17c may also be given the shape of a trough extending from one side to the other of the tensioning member, so that the bulges 17 of the tensioning member assume the shape of respective humps.

As a result, the raised portions or bulges 17 of the tensioning member 17 touch the threads outside of the individual knots 101, 102 in such a manner that when the individual knots 101, 102 are moved toward each other, the tensioning member does not enter into engagement with the individual knots.

When, during the knot-forming operations described above, the individual knots 161 and 102 are formed and slightly pulled together by the tie beaks 26, 27 (FIG. 6) and when thereafter the tie beaks move to the open position of FIG. 7 to thereby release the thread ends 0 and d, the tensioning member 17 moves upwardly (from FIG. 7 to MG. 8). During the latter stage, the knots 1111, 1192, prior to being tightened together, glide over the humps 17. This is possible because in this stage the threads are not yet under considerable tension so that the individual knots can still pass over the humps 17. This of course requires a sufficiently wide spacing between the humps 17. When the stage of FIG. 8 is reached, the knots 1111, 1112 have passed over the bumps 17' and are now'located within the recess where they are no longer retainable by the tensioning member 17. This corresponds to the position shown in FIG. 9. The individual knots can now be pulled tightly together Without interference by the tensioning member.

The design of the surface on the active end of the tensioning member that is to enter into contact with the threads is not limited to the particular embodiment illustrated. It is only essential that the tensioning member is iven such a shape that it does not prevent the individual knots from being pulled together, and hence that the end surface of the tensioning member cannot become an obstacle between the two individual knots. In some cases, it is already sufficient to give the recess 170 a convex curvature of a large curvature radius. On the other hand, some kinds of yarn make it necessary to make the tension- .ing member at its upper end so wide that the individual knots 101, 1112 are already located above the recess 170 at the beginning of the tensioning operation so that the knots need not glide over the humps 17.

It will be obvious to those skilled in the art, upon study of this disclosure, that knotters according to our invention can be modified in various respects and hence can be given embodiments other than particularly illustrated and described herein, without departing from the essential features of our invention and within the scope of the claims annexed hereto.

We claim:

1. A yarn-tying device for knotting two threads together, comprising two mutually spaced tying means each being engageable with one of the respective threads at a location thereof relatively near the thread end and also with the other thread at a location of the latter relatively remote from the end of said other thread to form in said one thread an individual knot around the other thread, a tensioning member movable in a direction transverse to the spacing direction of said two tying means, said tensioning member having a front portion engageable with the two threads between said two tying means when said member moves toward said spacing :direction -for thereby causing the individual knots to be tightened against each other, said front portion of said tensioning member having means defining a recess spacing said knots from the surfaces of said front portion at the location occupied by the knots when in tightened condition.

2. In a yarn-tying device according to claim 1, said tensioning member and said recess being located midway between said two tying means.

3. In a yarn-tying device according to claim 1, said recess having the shape of a trough of rounded contour.

4. A yarn-tying device for knotting two threads together comprising two rotatable beak members spaced from each other, each beak member having means for clamping one of said thread ends and being engageable with the other thread at a point spaced from its clamped end, means for rotating said beak members so as to cause each to form in said one thread end an individual loop around the other thread, a tensioning member movable relative to said beak members :to strip saidindividual loops therefrom, drive means operatively connected with said beak members and with said tensioning member for imparting movement to said tensioning member and actuating said beak members to release the thread ends after forming said individual loops but prior to actuation of said tensioning member, said tensioning member having a thread-engaging surface portion and being movable to a position between said two beak members for causing said surface portion to pull said individual loops together, said tensioning member having in said surface portion means defining a recess spacing said loops from said surface portion at the location occupied by the two loops when fully pulled together.

Abbott Dec. 2, 1941 Furst Apr. 25, 1961 

1. A YARN-TYING DEVICE FOR KNOTTING TWO THREADS TOGETHER, COMPRISING TWO MUTUALLY SPACED TYING MEANS EACH BEING ENGAGEABLE WITH ONE OF THE RESPECTIVE THREADS AT A LOCATION THEREOF RELATIVELY NEAR THE THREAD END AND ALSO WITH THE OTHER THREAD AT A LOCATION OF THE LATTER RELATIVELY REMOTE FROM THE END OF SAID OTHER THREAD TO FORM IN SAID ONE THREAD AN INDIVIDUAL KNOT AROUND THE OTHER THREAD, A TENSIONING MEMBER MOVABLE IN A DIRECTION TRANSVERSE TO THE SPACING DIRECTION OF SAID TWO TYING MEANS, SAID TENSIONING MEMBER HAVING A FRONT PORTION ENGAGEABLE WITH THE TWO THREADS BETWEEN SAID TWO TYING MEANS WHEN SAID MEMBER MOVES TOWARD SAID SPACING DIRECTION FOR THEREBY CAUSING THE INDIVIDUAL KNOTS TO BE TIGHTENED AGAINST EACH OTHER, SAID FRONT PORTION OF SAID TENSIONING MEMBER HAVING MEANS DEFINING A RECESS SPACING SAID KNOTS FROM THE SURFACES OF SAID FRONT PORTION AT THE LOCATION OCCUPIED BY THE KNOTS WHEN IN TIGHTENED CONDITION. 